Direct Cooling Platform With Vapor Compression Refrigeration Cycle And Applications Thereof

ABSTRACT

A direct refrigeration cooling platform can cool high heat density sources such as LEDs, IC chip, power amplifiers and laser diodes. The platform utilizes a combination of technologies from a water cooled cold plate design and a vapor compression refrigeration system. The cold plate of the direct refrigeration cooling platform replaces an evaporator in a conventional vapor compression refrigeration cycle. High heat density sources are directly mounted onto the cold plate. Temperature of the cold plate is regulated based on temperature feedback and is maintained above ambient temperatures. For LED applications, a number of LEDs are mounted onto the cold plate of the direct refrigeration cooling platform. Beams of light are distributed via fiber optic light guides to remote and inaccessible locations, where light sources are to be replaced. IC chips are cooled the same way with IC chips attached to the cold plate of the direct refrigeration cooling platform.

CROSS REFERENCE TO RELATED PATENT APPLICATIONS

The present disclosure claims the priority benefit of U.S. PatentApplication Ser. No. 62/301,971, filed on 1 Mar. 2016, and U.S. PatentApplication Ser. No. 62/372,306, filed on 9 Aug. 2016, which areincorporated by reference in their entirety.

TECHNICAL FIELD

The present disclosure is generally related to image processing inelectronic apparatuses and, more particularly, to thermodynamics andheat transfer and, particularly, to a vapor compression refrigerationcooling system.

BACKGROUND

Unless otherwise indicated herein, approaches described in this sectionare not prior art to the claims listed below and are not admitted to beprior art by inclusion in this section.

Light emitting diodes (LEDs) have been used widely in medical tomilitary applications. One challenging problem for the usage of LEDs isthe removal of heat generated by the LEDs, so that the LEDs can operatewithin diode operating temperatures to avoid shortened life due tooperation under high temperature for a prolonged period of time. Acommon way to cool LEDs is to use a heatsink with a fan. However, in anenvironment of high-power LED operation, the use of a chiller is oftennecessary. The chiller circulates cold water and removes heat away fromLEDs. In a conventional chiller a vapor compression refrigeration systemis used to provide cold water. However, the use of a chiller with watercirculation tends to increase the form factor substantially as well asthe operating cost of an overall cooling system.

A vapor compression refrigeration cycle generally consists of acompressor, a condenser, an expansion valve, an evaporator and arefrigerant, which are elements of a recirculating circuit connected bytubing. The refrigeration cycle rejects heat at the condenser andabsorbs heat at the evaporator. Thus, the temperature in an environmentat and around the evaporator is typically lower than the surroundingambient environment. Moreover, work energy is required to drive thecycle at the compressor.

SUMMARY

The following summary is illustrative only and is not intended to belimiting in any way. That is, the following summary is provided tointroduce concepts, highlights, benefits and advantages of the novel andnon-obvious techniques described herein. Select and not allimplementations are further described below in the detailed description.Thus, the following summary is not intended to identify essentialfeatures of the claimed subject matter, nor is it intended for use indetermining the scope of the claimed subject matter.

The present disclosure proposes a new cooling apparatus which is hereinreferred to as a direct refrigeration cooling platform, which utilizes avapor compression refrigeration cycle to cool heat sources directly viaa cold plate. Different from the vapor compression refrigeration cycleemployed in conventional chillers, in various embodiments of a directrefrigeration cooling platform in accordance with the present disclosurethe cold plate may be used in lieu of an evaporator in the vaporcompression refrigeration system. Moreover, a refrigerant, instead ofwater which is typically used in conventional chillers, may be used as acooling medium for the cold plate. In various embodiments of the directrefrigeration cooling platform in accordance with the presentdisclosure, heat sources such as LEDs and integrated-circuit (IC) chipsmay be directly mounted onto the cold plate.

The direct refrigeration cooling platform may use a relatively smallvolume of a refrigerant such as, for example and without limitation,R-134a, R-410A and/or R-407C. Advantageously, this relatively smallvolume is sufficient to dissipate a large amount of energy while keepingthe form factor of the overall system small. In addition, no externalplumbing connections are required, thereby simplifying the installationand reducing the cost of ownership of a direct refrigeration coolingplatform in accordance with the present disclosure.

As heat sources such as LEDs and IC chips may be mounted onto the coldplate directly, the cold plate may be used as a heat spreader and mayfunction as or otherwise replace an evaporator. Heat from the heatsources may thus be directly absorbed by a refrigerant as therefrigerant undergoes a phase change from liquid to gas while flowingthrough the cold plate. Heat may then be rejected to an environment asthe refrigerant flows through a condenser, where the refrigerantundergoes a phase change from gas to liquid.

In various embodiments of the direct refrigeration cooling platform inaccordance with the present disclosure, the compressor and the thermalexpansion valve may be electronically controlled to regulate the flowrate of the refrigerant, or refrigerant flow rate. The compressor mayincrease a pressure of the refrigerant in a gaseous phase. Therefrigerant flow rate may be changed by changing a rotational speed, inrevolutions per minute (RPM), of the compressor. The thermal expansionvalve may decrease the pressure of the refrigerant in a liquid phase.The refrigerant flow rate may be changed by throttling up and down thethermal expansion valve.

In various embodiments of the direct refrigeration cooling platform inaccordance with the present disclosure, a temperature feedback controlmay be performed. Temperature sensors may be mounted onto the cold plateto sense the temperature(s) of the cold plate at one or more spots. Acentral processing unit (CPU) may detect temperature changes in the coldplate and transmit signals to control the RPM of the compressor and/orthe thermal expansion valve. Hence, temperature of the cold plate may bekept relatively constant regardless of the amount of heat transferredfrom the heat sources to the cold plate. The temperature of the coldplate may be kept above an ambient temperature to prevent any dew pointcondensation.

In one aspect, an apparatus may include: a compressor capable ofcompressing a refrigerant; a condenser capable of cooling and condensingthe refrigerant; a thermal expansion valve capable of evaporating atleast a portion of the refrigerant; a cold plate capable of receivingone or more heat sources for the one or more heat sources to be disposedon the cold plate; and a tubing connecting the compressor, thecondenser, the thermal expansion valve, and the cold plate such that therefrigerant undergoes a vapor compression refrigeration cycle as therefrigerant flows through the compressor, the condenser, the thermalexpansion valve and the cold plate via the tubing. At least a portion ofheat from the one or more heat sources may be absorbed by therefrigerant via the cold plate.

In some implementations, the cold plate may be made of a metallicmaterial, and wherein the metallic material comprises aluminum orcopper.

In some implementations, the cold plate may be made of a non-metalmaterial. In some implementations, the non-metal material may includesilicon, beryllium oxide or aluminum nitride.

In some implementations, when viewed from at least one angle, the coldplate may be round, oval, elliptical or polygonal in shape.

In some implementations, an outer surface of the cold plate may beplated, anodized or chem-filmed.

In some implementations, the cold plate may include one or more internalflow channels therein for the refrigerant to flow through the cold platein either a serial fashion or a parallel fashion.

In some implementations, a surface of the one or more internal flowchannels of the cold plate may have a plating thereon.

In some implementations, a surface of the cold plate exposed to anambient may be thermally insulated with paint, polymer coating, hardanodizing, or a thermal-insulation material.

In some implementations, the apparatus may also include a temperaturesensor, a first circuit and a second circuit. The temperature sensor maybe disposed on or embedded in the cold plate, and may be capable ofsensing a temperature of the cold plate and providing temperature dataindicating the sensed temperature. The first circuit may be associatedwith the compressor, and may be capable of detecting a rotational speedof the compressor and providing a first data indicating the detectedrotational speed. The first circuit may be also capable of adjusting therotational speed of the compressor in response to receiving a firstcontrol signal. The second circuit may be associated with the thermalexpansion valve, and may be capable of detecting a position of thethermal expansion valve and providing a second data indicating thedetected position. The second circuit may be also capable of adjustingthe position of the thermal expansion valve in response to receiving asecond control signal.

In some implementations, the apparatus may further include a centralprocessing unit (CPU) communicatively coupled to receive the temperaturedata, the first data, and the second data from the temperature sensor,the first circuit, and the second circuit, respectively. The CPU may becapable of controlling the temperature of cold plate by providing eitheror both of the first control signal and the second control signal to thefirst circuit and the second circuit, respectively.

In some implementations, the apparatus may further include an ambienttemperature sensor capable of sensing a temperature of an ambient inwhich the cold plate is situated. The CPU may maintain the temperatureof the cold plate above the sensed temperature of the ambient.

In some implementations, the CPU may be capable of receiving a userinput that sets a user-preset temperature, and the CPU may maintain thetemperature of the cold plate within a range of ±20° C. from theuser-preset temperature.

In some implementations, the CPU may maintain the temperature of thecold plate within a range of −40° C. to 150° C.

In some implementations, the apparatus may also include the one or moreheat sources. In some implementations, the one or more heat sources mayinclude at least a light emitting diode (LED), an integrated-circuit(IC) chip, an amplifier, or a laser diode. In some implementations, theapparatus may further include a fiber optic light guides coupled to theLED to guide at least a portion of a light emitted by the LED to aremote location. In some implementations, the one or more heat sourcesmay be directly mounted onto the cold plate by one or more screws, oneor more brackets, one or more springs, or a combination thereof. In someimplementations, the apparatus may further include a cover plate thatsecures the one or more heat sources onto the cold plate.

In some implementations, the apparatus may also include the refrigerant,which may be R-134a, R-410A or R-407C.

Advantageously, various embodiments of the direct refrigeration coolingplatform in accordance with the present disclosure may be used with anyheat source such as LEDs, IC chips, power amplifiers, laser diodes, andso on. For LED applications, a number of LEDs may be mounted onto thecold plate of the direct refrigeration cooling platform, and beams oflight may be delivered to remote illumination areas via fiber opticlight guides. Thus, change-out of the LEDs may be performed at an easilyaccessible and centralized location. For IC chip applications, IC chipsmay be directly mounted onto the cold plate. Thus, a large amount ofheat generated by the IC chips may be removed with a small heat-sinkingform factor.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the disclosure, and are incorporated in and constitutea part of the present disclosure. The drawings illustrateimplementations of the disclosure and, together with the description,serve to explain the principles of the disclosure. It is appreciablethat the drawings are not necessarily in scale as some components may beshown to be out of proportion than the size in actual implementation inorder to clearly illustrate the concept of the present disclosure.

FIG. 1 is a diagram of a high-level design of a direct refrigerationcooling platform, the various embodiments of which may be implemented inaccordance with the present disclosure.

FIG. 2 is a perspective view of an example implementation of a directrefrigeration cooling platform in accordance with an embodiment of thepresent disclosure.

FIG. 3 is a perspective view of an example implementation of a directrefrigeration cooling platform with fiber optic light guides inaccordance with an embodiment of the present disclosure.

FIG. 4 is a left perspective view of an example implementation of adirect refrigeration cooling platform with fiber optic light guides inaccordance with an embodiment of the present disclosure.

FIG. 5 is a detailed perspective view of an example implementation of acold plate and fiber optic light guides in accordance with an embodimentof the present disclosure.

FIG. 6 is a detailed exploded view of an example implementation of acold plate and fiber optic light guides in accordance with an embodimentof the present disclosure.

FIG. 7 is a perspective view of an example implementation of asingle-channel cold plate in accordance with an embodiment of thepresent disclosure.

FIG. 8 is a perspective view of an example implementation of amultiple-channel cold plate with a series flow in accordance with anembodiment of the present disclosure.

FIG. 9 is a perspective view of an example implementation of amultiple-channel cold plate with a parallel flow in accordance with anembodiment of the present disclosure.

FIG. 10 is a tunnel LED lighting application with a direct refrigerationcooling platform and fiber optic light guides in accordance with anembodiment of the present disclosure.

FIG. 11 is an automobile LED headlamp lighting application with a directrefrigeration cooling platform and fiber optic light guides inaccordance with an embodiment of the present disclosure.

FIG. 12 is an ultraviolet (UV) LED lighting application for drying inkson paper during printing operation using a direct refrigeration coolingplatform and fiber optic light guides in accordance with an embodimentof the present disclosure.

FIG. 13 is a perspective view of an IC chip cooling application with adirect refrigeration cooling platform in accordance with an embodimentof the present disclosure.

FIG. 14 is a left perspective view of an IC chip cooling applicationwith a direct refrigeration cooling platform in accordance with anembodiment of the present disclosure.

FIG. 15 is a perspective view of a vehicle refrigeration system with adirect refrigeration cooling platform in accordance with an embodimentof the present disclosure.

FIG. 16 is a perspective view of on-demand air/water sterilizationsystem with a direct refrigeration cooling platform in accordance withan embodiment of the present disclosure.

DETAILED DESCRIPTION Overview

Various embodiments disclosed herein pertain to a direct refrigerationcooling platform, which utilizes a vapor compression refrigerationcycle. Compared to conventional chillers, embodiments of the directrefrigeration cooling platform in accordance with the present disclosuredoes not require a bulky water-based heat exchange system. Moreover,external plumbing is eliminated in embodiments of the directrefrigeration cooling platform in accordance with the presentdisclosure.

FIG. 1 depicts a high-level design of a direct refrigeration coolingplatform 100, the various embodiments of which may be implemented inaccordance with the present disclosure. Referring to FIG. 1, directrefrigeration cooling platform 100 may include a vapor compressionrefrigeration cycle including four major components, namely a cold plate101, a compressor 102, a condenser 103 and a thermal expansion valve104. On the one hand, compressor 102, condenser 103 and thermalexpansion valve 104 may be implemented with a compressor, condenser anda thermal expansion valve similar to those employed in conventionalvapor compression refrigeration cycles. On the other hand, theevaporator in conventional vapor compression refrigeration cycles isreplaced by cold plate 101 in direct refrigeration cooling platform 100.

In a thermodynamic cycle of direct refrigeration cooling platform 100, acirculating refrigerant enters compressor 102 as a vapor. The vapor iscompressed at constant entropy and exits compressor 102 superheated. Thesuperheated vapor travels through condenser 103, which first cools andremoves the superheat from the vapor and then condenses the vapor into aliquid by removing additional heat at constant pressure and temperature.The liquid refrigerant goes through thermal expansion valve 104 wherethe pressure of the refrigerant abruptly decreases, causing flashevaporation and auto-refrigeration of at least a portion of the liquid.This results in a mixture of liquid and vapor at a lower temperature andpressure. The cold liquid-vapor mixture then travels through cold plate101 and is completely vaporized by cooling one or more heat sourcesdisposed on or otherwise in contact with cold plate 101. The resultingrefrigerant vapor returns to compressor 102 to complete thethermodynamic cycle.

Cold plate 101 may be made of a metallic material with a high thermalconductivity such as, for example and without limitation, aluminum,copper or aluminum nitride for a uniform and fast heat transfer.Alternatively, cold plate 101 may be made of a non-metal material with ahigh thermal conductivity such as, for example and without limitation,silicon, beryllium oxide, aluminum nitride or a type of ceramics. Coldplate 101 may be used to function as a heat spreader and heatsink.

One or more heat-generating devices, or heat sources, may be directlymounted on, coupled to, affixed to or otherwise disposed on cold plate101 such that at least a portion of the heat in the one or more heatsources may be transferred to cold plate 101 by thermal conduction. Forexample, heat sources such as LEDs may be directly mounted onto coldplate 101 by means of, for example and without limitation, soldering,brazing or mechanically secured with screws or/and brackets or/andsprings. Cold plate 101 may thus provide both electrical insulation andthermal conduction.

In direct refrigeration cooling platform 100, any suitable refrigerantmay be used to flow through the refrigeration cycle. Refrigerant suchas, for example and without limitation, R-134a, R-410A and R-407C may beutilized in direct refrigeration cooling platform 100. Accordingly, coldplate 101 may have one or more internal flow channels for therefrigerant to flow through cold plate 101. The one or more internalflow channels of cold plate 101 may be arranged in series or inparallel. That is, the one or more internal flow channels may beconfigured or arranged such that the refrigerant may flow through coldplate 101 in a serial fashion or in a parallel fashion.

Cold plate 101 may have two or more holes corresponding to the one ormore internal flow channels. Inlet and outlet ports may be soldered ontosuch holes of cold plate 101. Pipe threads may be tapped onto the holesof cold plate 101. Moreover, cold plate 101 may have through holesand/or tapped screw holes that may be used for securing diodes, IC chipsand any heat source components onto cold plate 101. The outer surface ofcold plate 101 may be plated with zinc, nickel or chrome to preventsurface oxidization. In cases in which cold plate 101 is made ofaluminum, the outer surface of cold plate 101 may be chem-filmed oranodized. As for the internal flow channels of cold plate 101 throughwhich the refrigerant flows, there may be no finishes or, alternatively,may have a plating on the surfaces thereof.

When viewed from at least one angle, cold plate 101 may be round, oval,elliptical or polygonal in shape. For example, cold plate 101 may betriangular, square, rectangular, pentagonal, hexagonal or octagonal.Edges and corners of cold plate 101 may be rounded off to reduce surfaceareas. Surfaces of cold plate 101 that are exposed to an ambient mayabsorb heat from the surrounding. Such surfaces may be thermallyinsulated by a paint, rubber coating, polymer coating, insulation foam,hard anodizing or any other suitable thermal-insulation technique.

In direct refrigeration cooling platform 100, a feedback control systemthat includes a central processing unit (CPU) 174 may be provided. CPU174 may be implemented in the form of one or more integrated-circuit(IC) chips such as, for example and without limitation, one or moresingle-core processors, one or more multi-core processors, or one ormore complex-instruction-set-computing (CISC) processors. Moreover, CPU174 may be implemented as one or more processors of a computingapparatus such as, for example and without limitation, a smartphone, alaptop computer, a notebook computer, a tablet computer, a desktopcomputer, a server, a wearable computing device, any combination of twoor more thereof, or any variation thereof.

As illustrated in FIG. 1, CPU 174 may be coupled to receive temperaturedata regarding one or more temperature readings on one or more spots ofcold plate 101. Additionally, CPU 174 may be coupled to receivecompressor data (e.g., RPM) from compressor 101 as well as valve data(e.g., valve positioning being fully closed, fully open, ½ open, ⅓ open,¼ open, ¾ open and so on) from thermal expansion valve 104. Furthermore,CPU 174 may be coupled to transmit control signals to control each ofcompressor 102 and thermal expansion valve 104 to control a flow rate ofthe refrigerant and thereby adjust or maintain a temperature of coldplate 101. For instance, direct refrigeration cooling platform 100 mayinclude a number of temperature sensors mounted on or otherwise coupled,affixed or attached to cold plate 101 to sense the temperature(s) of oneor more spots of cold plate 101 and provide temperature data to CPU 174.

In operation, CPU 174 may, based on the temperature data, detecttemperature changes in cold plate 101 and, as a result, transmit controlsignal(s) to either or both of compressor 102 and thermal expansionvalve 104 to increase or decrease the RPM of compressor 102 and/or tothrottle up or down thermal expansion valve 104. The control signal(s)from CPU 174 to either or both of compressor 102 and thermal expansionvalve 104 may cause the flow rate of the refrigerant to increase ordecrease to adjust the rate at which heat, or thermal energy, in coldplate 101 is carried away by refrigerant, thereby increasing ordecreasing the temperature of cold plate 101. For example, to lower ordecrease the temperature of cold plate 101, CPU 174 may transmit controlsignal(s) to decrease the RPM of compressor 102 and/or throttle downthermal expansion valve 104.

In some embodiments, CPU 174 may maintain the temperature of cold plate101 above an ambient temperature to prevent any dew point condensationfrom forming. For example, there may be one or more temperature sensorsarranged to sense the ambient temperature and provide temperature data,indicating the sensed ambient temperature, to CPU 174. Thus, CPU 174 maymaintain the temperature of cold plate 101 based on the sensed ambienttemperature by controlling the RPM of compressor 102 and/or valveposition (between being fully open and being fulling closed) of thermalexpansion valve 104.

In some embodiments, CPU 174 may accept user input from a user to presetor otherwise predefine a desired temperature of cold plate 101.Accordingly, CPU 174 may maintain a temperature of cold plate 101 withina certain range of the desired temperature preset by the user (e.g.,within a range of ±10° C. thereof), with the minimum temperature of coldplate 101 being kept above the ambient temperature. Thus, an operationaltemperature range of cold plate 101 may be in the range of −40° C. to150° C.

For illustrative purposes and without limiting the scope of the presentdisclosure, a number of example implementations based on directrefrigeration cooling platform 100 are described below with reference toFIGS. 2-16.

Example Implementations

FIG. 2 depicts an example implementation of a direct refrigerationcooling platform 5001 in accordance with an embodiment of the presentdisclosure. FIG. 3 depicts an example implementation of a directrefrigeration cooling platform 5001 with fiber optic light guides 3001in accordance with an embodiment of the present disclosure. FIG. 4depicts an example implementation of a direct refrigeration coolingplatform 5001 with fiber optic light guides 3001 in accordance with anembodiment of the present disclosure. FIG. 5 depicts an exampleimplementation of cold plate 201 and fiber optic light guides 3001 inaccordance with an embodiment of the present disclosure. FIG. 6 depictsan example implementation of cold plate 201 and fiber optic light guides3001 in accordance with an embodiment of the present disclosure. FIG. 7depicts an example implementation of a single-channel cold plate 201 inaccordance with an embodiment of the present disclosure. FIG. 8 depictsan example implementation of a multiple-channel cold plate 291 with aseries flow in accordance with an embodiment of the present disclosure.FIG. 9 depicts an example implementation of a multiple-channel coldplate 311 with a parallel flow in accordance with an embodiment of thepresent disclosure.

The following components are shown in FIGS. 2-9: cold plate 201,compressor 202, condenser 203, thermal expansion valve 204, cover plate212, holder of fiber optic light guide 213, fiber optic light guide #1214, light emitting diode (LED) 215, base plate 216, thermal interfacematerial 217, fiber optic light guide #2 218, fiber optic light guide #3219, beam of light 220, outlet hole #1 of refrigerant flow and tubeconnection 241, through hole or tapped screw hole #1 242, through holeor tapped screw hole #n 243, inlet hole #1 of refrigerant flow and tubeconnection 244, internal flow channel #1 of single-channel cold plate245, tube connection between cold plate and thermal expansion valve 251,tube connection between cold plate and compressor 252, tube connectionbetween condenser and compressor 253, tube connection between condenserand thermal expansion valve 254, printed circuit board assembly (PCBA)of CPU, compressor power and RPM control 261, PCBA of thermal expansionvalve control and power 262, temperature sensor #1 265, temperaturesensor #2 266, voltage cable for compressor power 271, ground cable forcompressor power 272, signal cable for compressor RPM control 273,central processing unit (CPU) 274, temperature probe cable #1 275,temperature probe cable #2 276, signal cable for thermal expansion valvecontrol 277, mounting plate for direct refrigeration cooling platform281, cold plate with multiple internal flow channels in a series flow291, outlet hole #2 of refrigerant flow and tube connection 292, inlethole #2 of refrigerant flow and tube connection 293, internal flowchannel #1 of multiple-channel cold plate in a series flow 294, internalflow channel #2 of multiple-channel cold plate in a series flow 295,internal flow channel #n of multiple-channel cold plate in a series flow296, tube #1 for refrigerant channel connection in multiple-channel coldplate in a series flow 297, tube #2 for refrigerant channel connectionin multiple-channel cold plate in a series flow 298, through hole ortapped screw hole #10 299, cold plate with multiple internal flowchannels in a parallel flow 311, outlet hole #10 of refrigerant flow312, inlet hole #10 of refrigerant flow 313, internal flow channel #1 ofmultiple-channel cold plate in a parallel flow 314, internal flowchannel #2 of multiple-channel cold plate in a parallel flow 315,internal flow channel #n of multiple-channel cold plate in a parallelflow 316, tube #10 for refrigerant channel connection inmultiple-channel cold plate in a parallel flow 317, tube #11 forrefrigerant channel connection in multiple-channel cold plate in aparallel flow 318, and through hole or tapped screw hole #20 319.

In direct refrigeration cooling platform 5001, a cold plate 201 replacesan evaporator in a conventional vapor compression refrigeration system,which typically consists of an evaporator. Direct refrigeration coolingplatform 5001 also includes a condenser 203, a thermal expansion valve204 and a compressor 202. Cold plate 201 may be made of a metallicmaterial or a non-metal material with a high thermal conductivity suchas aluminum, copper, aluminum nitride or silicon for a uniform and fastheat transfer.

In at least one embodiment, LEDs 215 may be directly mounted onto coldplate 201 by means of soldering, brazing or mechanically secured withscrews or/and brackets or/and springs. Cold plate 201 may function as aheat spreader and heatsink for LEDs 215.

In at least one embodiment, LEDs 215 may be packaged with the baseplate, 216, made of non-metals with a high thermal conductivity such assilicon, beryllium oxide or aluminum nitride are directly mounted ontothe cold plate, 201, by means of soldering, brazing or mechanicallysecured with screws or/and brackets or/and springs. The base plate witha high thermal conductivity provides electrical insulation whileproviding a high thermal conduction path.

In at least one embodiment, cover plate 212 may be made of a metallicmaterial or a non-metal material with a high thermal conductivity suchas aluminum or copper. Cover plate 212 may be used to secure diodes 215(or any other type of heat source(s)) to the cold plate 201. With thethermal interface material 217, such as indium for example, insertedbetween cold plate 201 and diodes 215, material thermal expansionmismatch between cold plate 201 and diodes 215 may be eliminated. Thecover plate 212 may be used as a heatsink and mounted using screwsor/and brackets.

In at least one embodiment, refrigerants such as R-134a, R-410A andR-407C may flow through internal flow channel(s) of cold plate 201 whereinlet and outlet ports of the cold plate 201 are soldered onto coldplate holes 241 and 244. Pipe threads may be also tapped on cold plateholes 241 and 244. Cold plate 201 may have through holes or/and tappedscrew holes 242 and 243, which can be used for securing diodes, IC chipsand any heat source components onto cold plate 201. The outer surface ofcold plate 201 may be plated with zinc, nickel or chrome to preventsurface oxidization. In cases in which cold plate 201 is made ofaluminum, the outer surface of cold plate 201 may be chem-filmed oranodized. Internal flow channels 245, 294, 295, 296, 314, 315 and 316 ofcold plates 201, 291 and 311 may have no finishes or, alternatively, mayhave a plating on the surfaces thereof.

In at least one embodiment, the shape of cold plates 201, 291 and 311may be rectangular, square, triangular, round, hexagonal or octagonal.Edges and corners are rounded off to reduce surface areas. Cold platesurfaces exposed to an ambient will absorb heat from the surrounding.These surfaces can be thermally insulated with a paint, rubber coating,polymer coating, insulation foam, hard anodizing or any suitablethermal-insulation technique.

In at least one embodiment, temperature sensors 265 and 266 may beattached to the cold plate 201. Temperature sensors are used to controlthe flow rate of refrigerants such as R-134a, R-410A and R-407C. As thecold plate temperature increases, CPU 274 may detect temperature changesvia temperature sensors 265 and 266, and may transmit control signals toincrease the RPM of compressor 202 or/and to throttle up thermalexpansion valve 204. These inputs may cause the refrigerant flow rate toincrease and the cold plate temperature to decrease. To decrease thecold plate temperature, the RPM of compressor 202 may be decreasedor/and thermal expansion valve 204 may be throttled down. Hence, afeedback control system is established.

In at least one embodiment, cold plate 201 may be kept above the ambienttemperature to prevent any dew point condensation. CPU 274 may detectthe ambient temperature and keep cold plate 201 above the ambienttemperature by controlling the RPM of compressor 202 or/and position ofthermal expansion valve 204. When the cold plate temperature is presetby a user, direct refrigeration cooling platform 5001 may be operated atthe preset temperature ±10° C., where the minimum temperature may beabove the ambient temperature. An operational temperature range of thecold plate 201 may be, for example and without limitation, in the rangeof −40° C. to 150° C.

As cold plate 291 and cold plate 311 are variations of cold plate 201,some or all of the above-described features of cold plate 201 are alsoapplicable to cold plate 291 and cold plate 311. Thus, in the interestof brevity, a detailed description of each of cold plate 291 and coldplate 311 is not provided herewith to avoid redundancy.

In at least one embodiment, various LEDs such as ultra violet (UV),white light and infrared (IR) may be cooled using the directrefrigeration cooling platform 5001. Beams of light may be deliveredwith or without fiber optic light guides 3001. The direct refrigerationcooling platform 5001 may cool multiple LEDs in a centralized locationand delivers beams of light to remote illumination areas via fiber opticlight guides. Advantages of using direct refrigeration cooling platform5001 include, for example and without limitation: 1) LEDs will operateat user's preset temperature with no risk of diode overheating; 2) noLED needs to be replaced at illumination areas, as all LEDs are replacedat a centralized ground location; and 3) there is no risk of the LEDwavelength shift due to overheating of LEDs because a relativelyconstant temperature is maintained in the cold plate.

FIG. 10 depicts a tunnel LED lighting application 6001 with a directrefrigeration cooling platform and fiber optic light guides inaccordance with an embodiment of the present disclosure. FIG. 11 depictsan automobile LED headlamp lighting application 7001 with a directrefrigeration cooling platform and fiber optic light guides inaccordance with an embodiment of the present disclosure. FIG. 12 depictsan UV LED lighting application 8001 for drying inks on paper duringprinting operation using a direct refrigeration cooling platform andfiber optic light guides in accordance with an embodiment of the presentdisclosure. FIG. 13 depicts a perspective view of an IC chip coolingapplication 9001 with a direct refrigeration cooling platform inaccordance with an embodiment of the present disclosure. FIG. 14 depictsa left perspective view of IC chip cooling application 9001. FIG. 15depicts a perspective view of a vehicle refrigeration system 9500 with adirect refrigeration cooling platform in accordance with an embodimentof the present disclosure. FIG. 16 depicts a perspective view ofon-demand air/water sterilization system 9600 with a directrefrigeration cooling platform in accordance with an embodiment of thepresent disclosure.

The following components are shown in FIGS. 10-16: fiber optic lightguide #1 601, fiber optic light guide #2 602, fiber optic light guide #3603, fiber optic light guide #4 604, fiber optic light guide #5 605,tunnel 609, automobile 610, paved road 611, right fiber optic lightguide 710, left fiber optic light guide 711, left light reflector 712,right light reflector 713, left LED 721, right LED 722, fiber opticlight guide #1 801, fiber optic light guide #2 802, fiber optic lightguide #3 803, fiber optic light guide #4 804, fiber optic light guide #5805, fiber optic light guide #6 806, fiber optic light guide #7 807,fiber optic light guide holder 811, left printing roller 812, rightprinting roller 813, roll of paper 815, direction of right rollerrotation 817, direction of left roller rotation 818, beams of light 820,bottom PCBA with IC chip 901, top PCBA with IC chip 902, IC chip on topPCBA 905, IC chip on bottom PCBA 906, manifold of refrigerant flow 92,heat-generating component 921, vehicle evaporator 922, evaporator fan923, thermal expansion valve for vehicle evaporator 925, thermalexpansion valve for vehicle LED headlights 926, thermal expansion valvefor heat-generating components 927, cold plate for heat-generatingcomponents 928, cold pate for vehicle LED headlights 929, temperaturesensor at cold plate of heat-generating components 931, temperaturesensor at cold plate of vehicle LED headlights 932, tube connectionbetween evaporator and manifold 941, tube connection between cold plateand manifold 942, optically clear water pipe or air duct 951, holder ofUV-LED fiber optic light guides 952, outlet pipe 953, inlet pipe 954,outlet flow sensor 955, inlet flow sensor 956, direction of fluid atoutlet 957, direction of fluid at inlet 958, fiber optic light guide #1961, fiber optic light guide #2 962, fiber optic light guide #3 963,fiber optic light guide #4 964, LEDs and fiber optic light guides 3001,vehicle air conditioning system (including thermal expansion valve)4001, vehicle LED headlight cooling system (including thermal expansionvalve) 4002, vehicle heat-generating component cooling system includingthermal expansion valve 4003, direct refrigeration cooling platform5001, direct refrigeration cooling platform with a refrigerantdistribution manifold 5002, tunnel LED lighting application 6001,automobile LED headlight application 7001, UV LED lighting application8001, IC chip cooling application 9001, vehicle refrigeration system9500, and on-demand air/water sterilization system 9600 with UVC-LEDs.

In FIGS. 13 and 14, direct refrigeration cooling platform 5001 may beused to cool IC chips 905 and 906 in PCBAs 901 and 902. The top of ICchips, where heat-sinking is normally performed, may be directlyattached to cold plate 201. Direct refrigeration cooling platform 5001may keep the cold plate temperature relatively constant and above theambient temperature regardless of the amount of heat output from ICchips 905 and 906. All of these are accomplished by the feedback controlfunction of the direct refrigeration cooling platform 5001.

FIG. 15 illustrates a vehicle refrigeration system 9500 with a directrefrigeration cooling platform 5002, which has a refrigerantdistribution manifold 920. The vehicle refrigeration system 9500 maycontain a vehicle air conditioning system 4001, a vehicle LED headlightcooling system 4002, and a vehicle heat producing component coolingsystem 4003. Thermal expansion valves 925, 926 and 927 may control therefrigerant flow rate on each cooling system. When not used, the coolingsystem 4002 may be shut off by thermal expansion valves 925, 926 and927. Manifold 920 may distribute a refrigerant to each cooling system.

FIG. 16 illustrates an UVC-LED on-demand air/water sterilization system9600 with direct refrigeration cooling platform 5001. Delivery of a highsterilization dose is achievable with the direct refrigeration coolingplatform 5001. The system 9600 may be designed to operate on demand asthe ultraviolet (UVC) light turns on when flow sensors 955 and 956detect flow of a fluid to be sterilized. The UVC light may turn off whenno flow is detected. The system 9600 may be designed to deliverreduction in air/water borne pathogens by at least a magnitude of 2 logas fluid passes through pipe 951.

In view of the above, some features of the present disclosure arehighlighted below.

LEDs (or another type of heat sources) may be directly mounted onto thecold plate of the direct refrigeration cooling platform to remove heat.

Heat sources such as an IC chip and laser diode may be directly mountedonto the cold plate of the direct refrigeration cooling platform toremove heat.

LEDs (or another type of heat sources) may be directly mounted onto thecold plate by means of soldering, brazing or mechanically secured withscrews or/and brackets or/and springs.

Heat sources such as an IC chip and laser diode may be directly mountedonto the cold plate by means of mechanically secured with screws or/andbrackets or/and springs.

LEDs packaged in the base plate made of non-metals with a high thermalconductivity, such as silicon, beryllium oxide or aluminum nitride, maybe directly mounted onto the cold plate by means of soldering, brazingor mechanically secured with screws or/and brackets or/and springs.

Cold plates made of a metal or non-metal with a high thermalconductivity may be attached to the evaporator section of a vaporcompression refrigeration cycle.

Cold plates may have through holes or/and tapped screw holes forsecuring LEDs, IC chips, and any heat sources.

Cold plates may have internal flow channel(s) built in for a refrigerantflow. The internal flow channels may be arranged either in parallel orin series.

Cold plate surface areas exposed to an ambient may be thermallyinsulated with a paint, polymer coating, hard anodizing or/and anythermal-insulation materials.

Cover plate made of a metal or non-metal may be used to secure diodesonto the cold plate to eliminate thermal stresses in between the coldplate and diodes.

Temperature sensors may be mounted on or embedded in the cold plate ofthe direct refrigeration cooling platform to provide temperaturereadings of the cold plate to a CPU of a feedback control system.

Execution of feedback control of the direct refrigeration coolingplatform may be accomplished by detecting temperatures from sensorsattached to the cold plate and then transmitting control signals tocontrol the flow rate of refrigerant by RPM changes in the compressoror/and throttling up/down of the thermal expansion valve.

An operational temperature range of the cold plate may be in a range of−40° C. to 150° C. in the direct refrigeration cooling platform.

The cold plate may be rectangular, square, round, triangular, hexagonalor octagonal in shape. Edges and corners may be rounded off to reducesurface areas.

An outer surface of the cold plate may be plated, anodized orchem-filmed. Internal flow channels of the cold plate may have nofinishes or/and have a plating on them.

The CPU in the direct refrigeration cooling platform may maintain thetemperature of cold plate above the ambient temperature via feedbackcontrol. Alternatively or additionally, the CPU in the directrefrigeration cooling platform may maintain the temperature of coldplate at a user's preset temperature ±20° C. or less via feedbackcontrol.

The cold plate may be kept above the ambient temperature to prevent anydew point condensation. A fan may be utilized to blow air onto the coldplate as an additional condensation prevention.

LEDs may be centralized using the direct refrigeration cooling platform,and beams of light may be delivered to remote illumination areas viafiber optic light guides.

LED sources may be centralized with other types of cooling platformssuch as a forced convection, water chiller and air conditioning cooling,and beams of light are delivered to remote illumination areas via fiberoptic light guides.

The top of IC chips, where heat-sinking is normally performed, may bedirectly attached to the cold plate in the direct refrigeration coolingplatform.

A direct refrigeration cooling platform with less than 500 W capacitymay be used for a single illumination application, where it is notcentralized, and may also be used for IC chip cooling.

The direct refrigeration cooling platform may be part of the vehiclerefrigeration system, cooling vehicle LED headlights and other heatproducing components in a vehicle.

With the direct refrigeration cooling platform with fiber optic lightguides, change of LEDs in remote and hazardous locations such as atunnel, bridge and nuclear power plant is not needed. The lifetime ofLEDs is maximized due to a constant temperature maintained at the coldplate regardless of the ambient temperature and the amount of heatproduced by LEDs.

With the direct refrigeration cooling platform with fiber optic lightguides, automobile headlight LED sources may be cooled. The lifetime ofLEDs is maximized due to a constant temperature maintained at the coldplate regardless of the ambient temperature and the amount of heatproduced by LEDs.

With the direct refrigeration cooling platform with fiber optic lightguides, the operation of drying inks on a paper printing may be fasterbecause high power UV LEDs can be used. The lifetime of UV LEDs ismaximized due to a constant temperature maintained at the cold plateregardless of the ambient temperature and the amount of heat produced byUV LEDs.

With the direct refrigeration cooling platform with fiber optic lightguides, on-demand air/water sterilization with UVC-LEDs may be possiblebecause high power UVC-LEDs can be used. The lifetime of UVC-LEDs ismaximized due to a constant temperature maintained at the cold plateregardless of the ambient temperature and the amount of heat produced byUVC-LEDs.

With the direct refrigeration cooling platform, IC chips may be directlycooled by attaching the cold plate onto the top of an IC chip, where aheatsink is normally attached to. A constant temperature may bemaintained at the cold plate regardless of the ambient temperature andthe amount of heat produced by the IC chip.

Any heat producing components may be directly cooled by attaching thecold plate onto the component. A constant temperature may be maintainedat the cold plate regardless of the ambient temperature and the amountof heat produced by the heat producing component.

Additional Notes

From the foregoing, it will be appreciated that various implementationsof the present disclosure have been described herein for purposes ofillustration, and that various modifications may be made withoutdeparting from the scope and spirit of the present disclosure.Accordingly, the various implementations disclosed herein are notintended to be limiting, with the true scope and spirit being indicatedby the following claims.

What is claimed is:
 1. An apparatus, comprising: a compressor capable ofcompressing a refrigerant; a condenser capable of cooling and condensingthe refrigerant; a thermal expansion valve capable of evaporating atleast a portion of the refrigerant; a cold plate capable of receivingone or more heat sources for the one or more heat sources to be disposedon the cold plate; and a tubing connecting the compressor, thecondenser, the thermal expansion valve, and the cold plate such that therefrigerant undergoes a vapor compression refrigeration cycle as therefrigerant flows through the compressor, the condenser, the thermalexpansion valve and the cold plate via the tubing, wherein at least aportion of heat from the one or more heat sources is absorbed by therefrigerant via the cold plate.
 2. The apparatus of claim 1, wherein thecold plate is made of a metallic material, and wherein the metallicmaterial comprises aluminum or copper.
 3. The apparatus of claim 1,wherein the cold plate is made of a non-metal material.
 4. The apparatusof claim 3, wherein the non-metal material comprises silicon, berylliumoxide or aluminum nitride.
 5. The apparatus of claim 1, wherein, whenviewed from at least one angle, the cold plate is round, oval,elliptical or polygonal in shape.
 6. The apparatus of claim 1, whereinan outer surface of the cold plate is plated, anodized or chem-filmed.7. The apparatus of claim 1, wherein the cold plate comprises one ormore internal flow channels therein for the refrigerant to flow throughthe cold plate in either a serial fashion or a parallel fashion.
 8. Theapparatus of claim 1, wherein a surface of the one or more internal flowchannels of the cold plate has a plating thereon.
 9. The apparatus ofclaim 1, wherein a surface of the cold plate exposed to an ambient isthermally insulated with paint, polymer coating, hard anodizing, or athermal-insulation material.
 10. The apparatus of claim 1, furthercomprising: a temperature sensor disposed on or embedded in the coldplate, the temperature sensor capable of sensing a temperature of thecold plate and providing temperature data indicating the sensedtemperature; a first circuit associated with the compressor, the firstcircuit capable of detecting a rotational speed of the compressor andproviding a first data indicating the detected rotational speed, thefirst circuit also capable of adjusting the rotational speed of thecompressor in response to receiving a first control signal; and a secondcircuit associated with the thermal expansion valve, the second circuitcapable of detecting a position of the thermal expansion valve andproviding a second data indicating the detected position, the secondcircuit also capable of adjusting the position of the thermal expansionvalve in response to receiving a second control signal.
 11. Theapparatus of claim 10, further comprising: a central processing unit(CPU) communicatively coupled to receive the temperature data, the firstdata, and the second data from the temperature sensor, the firstcircuit, and the second circuit, respectively, the CPU capable ofcontrolling the temperature of cold plate by providing either or both ofthe first control signal and the second control signal to the firstcircuit and the second circuit, respectively.
 12. The apparatus of claim11, further comprising: an ambient temperature sensor capable of sensinga temperature of an ambient in which the cold plate is situated, whereinthe CPU maintains the temperature of the cold plate above the sensedtemperature of the ambient.
 13. The apparatus of claim 11, wherein theCPU is capable of receiving a user input that sets a user-presettemperature, and wherein the CPU maintains the temperature of the coldplate within a range of ±20° C. from the user-preset temperature. 14.The apparatus of claim 11, wherein the CPU maintains the temperature ofthe cold plate within a range of −40° C. to 150° C.
 15. The apparatus ofclaim 1, further comprising the one or more heat sources.
 16. Theapparatus of claim 15, wherein the one or more heat sources comprise atleast a light emitting diode (LED), an integrated-circuit (IC) chip, anamplifier, or a laser diode.
 17. The apparatus of claim 16, furthercomprising a fiber optic light guides coupled to the LED to guide atleast a portion of a light emitted by the LED to a remote location. 18.The apparatus of claim 15, wherein the one or more heat sources aredirectly mounted onto the cold plate by one or more screws, one or morebrackets, one or more springs, or a combination thereof.
 19. Theapparatus of claim 15, further comprising a cover plate that secures theone or more heat sources onto the cold plate.
 20. The apparatus of claim1, further comprising the refrigerant, wherein the refrigerant comprisesR-134a, R-410A or R-407C.